AIM: To observe the antagonistic effect of hydroxysafflor yellow A (HSYA) on the platelet activating factor (PAF). METHODS: Washed rabbit platelet (WRP) aggregation and rabbit polymorphonuclear leukocytes (PMNs) aggregation induced by PAF were observed by turbidimetric assay in vitro. The PAF receptor antagonistic effect of HSYA was investigated by radio ligand binding assay (RLBA). RESULTS: In RLBA the specific binding inhibition effect of HSYA was found to be concentration-dependent in three different [3H]PAF concentrations. In the experiments, WRP aggregation and rabbit PMNs aggregation induced by PAF (9.55 x 10(-10), 9.55 x 10(-6) mol.L-1) were both inhibited by HSYA in a concentration-dependent manner in vitro. The IC50 of HSYA to inhibit WRP and rabbit PMNs aggregation was 0.99 and 0.70 mmol.L-1, respectively. CONCLUSION: The PAF receptor binding can be antagonized by HSYA.
AIM: To observe the antagonistic effect of hydroxysafflor yellow A (HSYA) on the platelet activating factor (PAF). METHODS: Washed rabbit platelet (WRP) aggregation and rabbit polymorphonuclear leukocytes (PMNs) aggregation induced by PAF were observed by turbidimetric assay in vitro. The PAF receptor antagonistic effect of HSYA was investigated by radio ligand binding assay (RLBA). RESULTS: In RLBA the specific binding inhibition effect of HSYA was found to be concentration-dependent in three different [3H]PAF concentrations. In the experiments, WRP aggregation and rabbit PMNs aggregation induced by PAF (9.55 x 10(-10), 9.55 x 10(-6) mol.L-1) were both inhibited by HSYA in a concentration-dependent manner in vitro. The IC50 of HSYA to inhibit WRP and rabbit PMNs aggregation was 0.99 and 0.70 mmol.L-1, respectively. CONCLUSION: The PAF receptor binding can be antagonized by HSYA.